Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Contract No. DE-AC52-06NA25396, awarded by the United States Department of Energy. The government has certain rights in this invention.